Fuel injection pump



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Patented Oct. 4, 1938 UNIJ'ED STATES PATENT t GFFICE y,2,131,933 FUEL INJECTION PUMP Denis Tabor Brock and George Joseph Trapp,

London, England, assignors to Automotive Products Company Limited, London, England Application October 5, 1936, Serial No.'104,112

v In GreatBrltain October I4,1935

1 Claim.v

(Cl. S-154).

(Granted under the provisions o f sec. 14,` act of March 2, 1927; 357 0. G. 5)

another is adapted to deliver liquid fuel to theV respective engine cylinders.

It is the object of the present invention t0.

" l0 provide an improved construction ofpump unit actuated by a cam shaft disposed within a cam shaft casing, one wall at least of said. cam shaft casing may be itself hollow for the accommodation of a iilter device through which liquid isv 26 passed prior to entering into the injection cylin- Ader or cylinders, saidiilter device conveniently being iiat or plate-like in form and being disposed beneath the'usual cam shaft chamber.

The invention further provides in a liquid injection pump having a plurality of injection cylinders'within a pump body, said cylinders being arranged parallel with one another and in a common plane, a lter chamber which is formed integrally in the pump body and is elongated in ,form so that it extends for substantially the whole length of saidbody and in a direction parailel'with th'e aforesaid common plane.

A liquid injection pump is further providedv having a metal body which yis formed in one piece with a filter chamber containing aillter device comprising a receptacle composed of filtering material, said chamber being Vformed with an inlet opening communicating with the inte'rior of the lter device and a delivery opening for ,receiving liquid which has passed through said device. The improved iilter device according to the invention preferably ex` ,y tendsior substantially `the whole length of the pump body measured parallel with the yusual 5o driving spindle `'of the pump. A plurality of .separate iiltering devices may, of course, be provided and these may be arranged in series, so that the liquid passing through the rst is led into the second and so on. Moreover, in the preferred construction the lower wall of the cam shaft casing of the injection pump is hollow to provide a iilter compartment which is fiat in shape and which opens into one side of the pump, f this opening being closed normally by an elon gated cover and serving forv the insertion and 5 removal of the lter device. With this arrange- Ament a pair of chambers may conveniently be formed side by side for the reception of a pair of iilter devices, an inter-communicating passage being formed to connect the exterior of one filter 10 device with the interior of the other. Not only does the invention improve the utility of an injection pump unit but it also simplies the construction where a iilter is to be used, las it enables external connecting pipes between the 16 lter and thenormal inlet of the pump to be entirely dispensed with, suitable passages being formed in the body of the pump for conducting the liquid from the filter or filters to the injection pump inlet or to the feed pump, where such 2O pump is employed.

'I'he invention is illustrated by the various examples given inthe accompanying diagrammatic drawings in( which:

Figure 1 is a fragmentary side` elevation of an 25 injection pump unit partly in section von the imei-i of Figure 2;

Figure 2 is a fragmentary section on the line 2 2 ofFigure 1;

Figure 3 is a sectional plan on the line 3-t-3 of 30 Figure 2;

Figure 4- is a'viewcorresponding to Figure 3, but showing an arrangement in which two filters are used in series; t

Figure 5 is a fragmentary side elevation partly 35 in section showing a -form of filter .removable from Vthe end of the pump unit;

' Figure 6l is a` sectional elevation on the line 6-6 of Figure 5;

Figure '7 is a sectional end elevation showing/,0 a further location for the filter device, which latter is also removable from the end of the pump unit; i

Figure 8 is a sectional end elevation showing a construction in which the filter device is re- 45 movable from the side of the pump unit;

Figure 9 is a sectional side elevation of afurther arrangement utilising acylindrical lter device removable from the end of the pump unit;

Figure 10 is a sectional elevation on the'line 50 'inlo of Figure 9; and a cylinder injection pump unit is shown compris- 55 ing a metal casting I forming the body of the pump, the lower part of said casting being arranged to form a housing II for a cam shaft, indicated at I2, said housing comprising a' pair oi' side walls I3'and I4 and a bottom Il. The upper part of the cam shaft housing II is provided with any suitable tappet guide I6 for receiving the usual tappets, one of which is indicated at I1 in Figure 1, while the cam shaft I2 is provided with a pair of bearings indicated generally at I8 and I9 respectively. As is usual, the injection cylinders (not shown) are arranged vertically in line with their axes lying in a common plane which contains the axis oi the cam shaft I2, said plane coinciding with the line I-I in Figure 2.

At one end of the pump and driven by the cam shaft I2 is a feed pump 20 of any suitable form, adapted in the case illustrated to receive liquid .from the filter, as will be hereinafter explained, and deliver it through the pipe 2| to the usual inlet passage serving the injection cylinders.

In accordance with the present invention the bottom I 'of the cam shaft casing II is hollow and is formed with a substantially flat chamber 22 extending for the whole length of the pump unit as shown in Figure 1. 'Ihis chamber is so disposed that its mouth 23 extends along the side of the pump unit, and is inclined upwardly in relation to the innermost part of the chamber 22, said mouth being closed normally by an elongated cover plate 24 which is formed integrally with an inlet pipe fitting 26 adapted to be connected with a reservoir or other convenient source of liquid (not shown). The chamber 22 contains a filter device 21 which takes the form of a flat plate-like receptacle provided at its mouth with a fiange 26 which is normally held in firm contact with a shoulder 29 by means of a projection 30 formed upon the interior of the cover plate 24. The inner part of the chamber 22 is provided with a longitudinally extending passage 3| which communicates with the inlet passage 32 of the feed pump 20. The liquid therefore, after reaching the interior of the lter device 21 by way of the inlet pipe 26, passes through the wall of said device into the surrounding space 33, and thence passes through the passage 3| into the feed pump `2l), as will be seen in Figure 3.

It will thus beseen that'the filter chamber 22 which is formed integrally in the pump body I0, extends for substantially the whole length of the latter and has its longitudinal axis lying parallel with the above mentioned general plane containing the axes of the injection cylinders and indicated at I-I in Figure 2, said longitudinal axis also being parallel with the axis of the cam shaft I2. f

A slight modification is shown in Figure 4, in which a partition 34 divides the chamber into two parts indicated at 22a and 22b these having a common cover plate 24, which not only serves to close the two mouths of the chambers 22a and 22h but also holds in place a pair of filter devices 21a and 21h. The inlet pipe 26 feeds liquid into the interior of the filter device 21a, and after passing through the wall of thevdevice said liquid flows through a passage I6 connecting the outside of the filter device 21a with the inside of the filter device 21h. The liquid thereafter has to pass through the wall of the device 21b and escapes from the chambei through the passage 3l conveniently leading tc the feed pump or to the injection cylinders of the pump unit.y In this case, of course, the two chambers 22a and 22h are substantially fiat so as to occupy very little space in the bottom I5 lof the injection pump body, and they may, if

desired, be inclined in the manner shown in Figure 2 or may be arranged so that their general plane is level.

Figures 5 and 6 illustrate an arrangement in which the chamber, has its mouth at one end of the pump body I0, a cover plate 24 incorporating an inlet pipe 26 again being provided. In this case the flange 28 is provided upon the end of the filter device 21, while the outlet passage (not shown) from the chamber 22 is preferably formed at the end opposite to the cover plate 24. It will be seen from Figure 5 that the filter extends parallel with the axis of the cam shaft I2. A slight modification is shown in Figure 7 where the filter device 21 is similarl to that shown in Figures 5 and 6, but is accommodated within a chamber 22 formed alongside the injection cylinders, which latter are not shown, although the bore for the accommodation of one of the cylinder assemblies is indicated at 36. As before the longitudinal axis of the filter device 21 lies parallel with the common plane containing the axes of the injection cylinders and the chamber 22 reaches from end to end of the body casting of the pump unit. If desired, an air relief passage 38 having a screw plug 39 may lead from the highest part of the chamber 22 so as to enable air to be readily removed when the pump is being charged withvfliquid.

A somewhat modified form of filter device 21 is employed in the arrangement shown in lFigure 8, said device being in the form ofV a substantially shallow tray which is provided around its periphery with a ange 28 as before. 'I'he chamber 22 is also comparatively shallow and is provided with an outlet passage 3l taking the liquid which passes through the filter device 21.

Referring to Figures 9 and 10, the filter 'device 21 is in this case elongated, and is circular in cross-section, the cover plate 24 being made circular to correspond and being tted with an inlet passage, 26. After passing through the filter device 21 the liquid is delivered through a pipe 31 for usewhere required in the feed. pump or injection cylinders. For the accommodation of the filter device 21 the wall I3 of the cam shaft chamber II is bulged as shown in Figure l0, although in some cases, of course, a filter of this general form can easily be accommodated in the corner of the cam shaft chamber, is indicated by the circle 36 shown in broken lines. In Figure 11 the same sort of cylindrical filter device 21 is accommodated within a chamber 22 formed in the body I0 alongsidevthe injection cylinders in the same manner as the embodiment illustrated in Figure 7.

Means other than that described may, of course, be used for accommodating and securing the flat filter elements inproximity to the cam shaft chamber, and," if desired, said, elements may be arranged to be withdrawn in a longitudinal direction from either end of the injection pump unit. The filter chamberrmay, moreover be disposed in a substantially vertical plane alongside the front or rear side of the injection pump unit, said element again being disposed in a plane lying substantially parallel with the usual cam shaft.

IIS

It will be understood that the vactual filtering means may be of any known or suitable kind, and may for example consist of wire gauze, wire or fabric cloth, or alternatively special forms of filter may be employed, such as those comprising metal plates or other members held in spaced relationship so as to produce an edge filtering eiect. The flat construction of filter moreover may permit the use of elements similar in construction to the usual filter press, in which cloth filtering members are interspaced with rigid supporting plates or equivalent. The fllteringmeans may, of course, be connected in any desired part of the passage traversed by the fuel oil or equivalent liquid to be handled by the injection pump, and in cases where the. base portion of the injection pump unit is arranged to accommodate a plurality of filtering elements these can be connected independently with different parts of said passage.

What we claim is:

In a multi-cylinder' fuel injection pump unit having plungers arranged in line and actuated from below by a horizontal cam shaft disposed within a cam shaft casing, a feed pump driven by the cam shaft, a hollow Wall which forms the bottom of the cam shaft casing', the space within said wall serving as a filter-chamber and being formed with an elongated opening to the exterior, said opening extending along the pump body parallel with the cam shaft, an elongated cover closing said opening, a hollow f'llter element which is elongated and at in -shape v'disposed within said filter chamber with its mouth portion in register with the elongated opening and with its general plane inclined to the horizontal in order to facilitate the removal of said filter element,'a passage for liquid fuel leading through said cover into the interior of the lter element, and a pasports of the feed pump.

DENIS TABOR BROCK. GEORGE JOSEPH TRAPP. 

